Forging furnace



Feb. 25, 1969 r. Y. HEWLETT, .JR

FORGING FURNACE Sheet Filed March 9. 1967 F l G. l

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ATTORNEYS Feb. 25, 1969 r. Y. HEWLETT, JR

FOR'GING FuRNAcE Sheet Filed March 9, 1967 FlG.3

F'IG-4 N MH Ez vw mf ATTORNEYS Feb. z5, 1969 T. Y. HEWLETT, JR 3,429,562

FORGING FURNACE Filed March 9. 1967 FIG.

INVENTOR 7'/M07//V X //'W77'Jfe w, MKM M ATTORNEYS United States Patent O 8 Claims ABSTRACT F THE DISCLOSURE The forging furnace described herein comprises a metal shell which has a bottom wall, side walls and a back wall. A hearth of iirebrick is formed on the bottom wall. The side end walls are provided with a rst layer of insulating material, a second layer of insulating brick and a third inner layer of sections of cast refractory material which have interengaging edges. Roof sections of cast refractory -material are suspended from a roof lframe. In one form of the invention, front sections of cast refractory material are suspended :from a frame member. In another form of the invention, front sections of cast refractory material are xed on the front of the furnace with their lower edges in vertically spaced relation to the hearth.

Background of the invention In the building, rebuilding and repair of forging furnaces, it is common to -build the furnaces by the combined use of firebrick refractories and refractory cement or mortar. Such building, rebuilding and repair involve substantial labor and result in unpredictable quality and durability because of variations in the labor and materials involved. It further requires that the refractories be cured in situ.

In addition, in such prior art forging furnaces, the slot provided at the front of the furnace through which castings and the like are inserted for heating are xed in size so that no adjustment is possible.

Among the objects of the invention are to provide a forging furnace construction which incorporates substantial savings in labor since skilled brick-laying labor is eliminated; 4which can be built, rebuilt or repaired in a minimum of time; which requires no curing time for the refractories resulting in substantial material savings since it utilizes refractories designed specifically for zforged furnace operation; which incorporates refractory sections that are easily replaced, and do not require the use of refractory cement or wooden forms; which furnace has predictable refractory life; which furnace has an adjustable slot height at the front; which operates with less radiation and convection heat losses; which has substantially improved temperature uniformity and fuel eiciency; which results in lower furnace costs per ton of forgings and lower operating costs per ton of forgings; which utilizes interchangeable refractory sections thereby minimizing refractory inventory and minimizing or eliminating the necessity for standby service.

Summary The forging furnace described herein comprises a metal shell which has a bottom wall, side walls and a back wall. A hearth of iirebrick is formed on the bottom wall. The side end walls are provided with a rst layer of insulating material, a second layer of insulating brick and a third inner layer of sections of cast refractory material which have interengaging edges. Roof sections of cast refractory material are suspended from a roof frame. In one form of the invention, front sections of cast refractory material are suspended from a frame member. In another form of the invention, front sections of cast refractory ice material are fixed on the front of the :furnace with their lower edges in vertically spaced relation to the hearth.

Description of the drawings FIG. 1 is a front elevational view of a forging furnace embodying the invention.

FIG. 2 is a sectional view taken along the line 2-2 in FIG. 4.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 1.

FIG. 4 is a sectional view taken along the line 4-4 in FIG. l.

FIG. 5' is a fragmentary part sectional perspective View of a portion of a modified furnace.

FIG. 6y is a partly Idiagrammatic horizontal sectional view through a portion of the furnace.

FIG. 7 is a partly diagrammatic view similar to FIG. 6 showing a modified form of furnace.

Description Referring to FIGS. 1 4, the forging furnace embodying the invention comprises a metal shell 10 which has a bottom wall 11, side walls 12 and a back wall 13 joined together as by welding to form continuous surfaces. The shell is reinforced -by vertically extending angles 14 at the four corners and by vertical angles 1-5, 16 that extend vertically along the side and back Walls. Channels 17, 18 extend horizontally across the front of the shell. The corner members 14 extend vertically downwardly to `form legs for supporting the furnace. Plates 19 are welded to the lower ends of the members 14 in space relation to the lowermost end and a spring 20 is interposed between each plate 19 and a plate 21 to yieldingly support the furnace on the floor. A bolt 22 is threaded through plate 19, extends through the spring 20, and is welded to the plate 21.

As shown in FIG. 2, a hearth 25 is provided on the bottom wall 11 and comprises layers 26, 27, 28 of rebrick. The layers are progressively greater in fire resistance and durability vertically from the bottom wall 11 to the interior of the furnace.

An outer layer 29 of insulating block is provided along the side walls 12 and the back wall 13. An intermediate layer 30 of insulating brick is provided adjacent the outer layer 29. Finally, cast sections 31 of refractory material are provided along the interior of the layer 30. The sections 31 are rectangular and have flat top and bottom surfaces. `Each vertical edge is shaped to form a projection 32 and shoulder 33 that engages a complementary projection and shoulder of the adjacent section. The sections 31 are intertted as shown in FIG. 3.

As shown in FIGS. 1 4, horizontal channels 35, 36 extend along the upper ends of the shell across the tops of the members 14, 15, 16 to form a support for a roof fra-me 37 that is generally rectangular and has a peripheral flange 38 engaging the top web of the channels 35, 36. Transversely extending -I-beams 39 extend between the front and rear members of the frame 37. Roof sections 40 of cast refractory material which a-re -generally rect-angular in shape and have flat sides and ends are supported from the transverse members 3,9 by hook members 41 that are embedded in the sections 40 and telescoped over the lower web of the -members 39. As suspended the roof sections 40 abut one another in the manner shown in FIG. 2 with the endmost roof section 40 engaging the upper ends of the sections 31 along the sides of the furnace.

A horizontal frame member `45 is supported across the front of the furnace on the members 36 and suspends a plurality of sections 31 by hooks `41 across the front of the furnace with their lower edges in spaced relation to the hearth and their side edges in abutting relation (FIG. 1).

It can thus be seen that there has been provided a forging furnace that is readily assembled without the use of mortar or cement, which utilizes sections of cast refractory material that are of substantially identical construction and -which as a result can be readily rebuilt and repaired as well as initially built without the use of skilled labor. The avoidance of the use of uncured refractories and cement results in a more predictable performance of the forgin-g furnace.

The manner in which the substantially identical sections 31 can be assembled to form different furnaces is readily discernible by the diagrammatic views shown in FIGS. 6 and 7 wherein the same number of refractory sections are combined in FIG. 6 to produce a furnace that is longer and narrower than the furnace in PIG. 7.

:In a modified form or furnace, the same modular construction of the sections 31 can be used without a suspended roof and front wall. As shown in FIG. which is a perspective view of the hearth and refractory section structure only, the roof comprises blocks 41 that lrest upon the sections 31 and the front wall comprises blocks 50 that are supported by lintels 51 in fixed relation to the hearth. In this form of the invention, refractory cement can be used if desired between the refractory sections 50 and the lintels 51.

Satisfactory materials for the hearth and the outer layers 29, 30 are brick and blocks made by A. P. Green Fire Brick Company of Mexico, Mo. Specifically, the following materials made by the A. P. Green Fire Bric-k Company have produced satisfactory results:

Hearth layer 26 Ozark medium duty iireclay brick, dry process.

Hearth layer 27 Empire high duty reclay brick, dry process.

Hearth layer 28 KX-99, high-fired superduty ire brick. 2300 F. insulating brick. Block insulation, up

1900 F. eiciency.

The refractory sections which are previously cast and cured may have the following composition:

Layer 30 Layer 29 to Percent A1203 58.55 SiO2 34.18 Fe203 1.19 CaO 2.84 MO .12 Alkalis .45 TiO2 2.1 1 Ignition loss .l1

Alternatively, one or more of the layers of the hearth 25 may be made of cast refractory similar to the material of the 4refractory sections 31, 40'.

I claim:

1. In a forging furnace, the combination comprising a metal shell having a bottom wall, side walls and a back wall,

a plu-rality of blocks of iireclay brick covering the base wall and forming a hearth,

a layer of insulating block adjacent the side and back walls,

a second layer of insulating brick adjacent said insulating block on said side and back Walls,

and a plurality of cast sections of refractory material in side by side relation adjacent said second layer on said side and back walls,

said sections havin-g interengaging edges,

a plurality of roof sections of cast refractory material,

and means for supporting said roof sections above said hearth.

2. The combination set forth in claim 1 including a plurality of front sections of cast refractory material,

a frame member on said metal shell adjacent the front end of said metal shell,

said front sections having interengaging edges,

and means for suspending said front sections in side by side relation from said frame member adjacent the front of said furnace with the lower edges of said sections in spaced relation to the hearth.

3. The combination set forth in claim 1 wherein said interengaging yedges comprise step projections extending along one edge and complementary shoulders.

y4. The combination set forth in claim 1 including a plurality of front cast sections of refractory material,

`and means for supporting said sections on said hearth with the lower ends thereof in spaced relation to said hearth.

5. The combination set forth in claim 1 wherein said hearth comprises a plurality of layers of iirebrick material,

said layers being of progressively greater fire resistance in the layers from the metal shell upwardly to the floor of the hearth.

6. In a for-ging furnace, the combination comprising a metal shell having a bottom Wall, side walls and a back wall,

insulating material forming :a hearth,

a plurality of sections of cast refractory material 0n said side and back walls,

said sections having interengaging edges,

a roof frame mounted on said metal shell,

a plurality of spaced substantially horizontal members on said roof frame overlying said hearth,

a plurality of roof sections,

and means for slidably suspending said roof sections from said horizontal members.

7. The combination set forth in claim 6 wherein said horizontal members comprise I-beams,

said means for slidably suspending said roof sections from said horizontal members comprising hook members embedded in said roof sections and telescoped over the lower web of said I-beams.

i8. The combination set forth in claim 6 including a plurality of front sections of cast refractory material,

a substantially horizontal frame member on said metal shell adjacent the front end of said metal shell, said front sections having interengaging edges,

and means for suspending each said front section from said frame member adjacent the front of said furnace With the lower edges of said sections in spaced relation to the hearth.

References Cited 

